The present invention relates to a disk apparatus for positioning a recording head on a track of a rotary memory disk to read/write information, more particularly, to a magnetic disk apparatus in which it is prevented for a positioning mechanism from being brought into contact with the disk by an impact force acting on the disk apparatus to destroy the data stored on the disk.
A conventional magnetic disk apparatus is schematically shown in FIG. 1. In FIG. 1, numeral 15 denotes a disk for storing information, 18 denotes a spindle motor for rotating the disk and structured integrally with the disk, 34 denotes a slider with a head mounted thereon, 32 denotes a suspension for supporting the slider, 31 denotes a carriage arm for supporting the suspension, and 33 denotes a voice coil motor for driving the carriage arm. The head is flown by the slider with a slight gap on a disk surface, and positioned in a desired track on the disk by the voice coil motor.
The head is supported by the suspension and the carriage arm. The suspension applies a pressing load to the slider to balance with the flying force, and also serves to flexibly support the slider in a flying direction. The suspension is formed by press-working a thin plate (thickness of usually several tens of micrometers). On the other hand, the carriage arm supports the suspension, and serves to transmit the drive force from the voice coil motor to the suspension. The arm is formed of aluminum and usually has a thickness of several decimillimeters.
In recent years, the magnetic disk apparatus has been demanded to have a superior impact resistance. Not only a hand-carried 2.5 inch magnetic disk apparatus mounted on a note personal computer, but also a 3.5 inch magnetic disk have required good impact resistance.
The 3.5 inch magnetic disk apparatus provided with a long carriage arm has a problem that the carriage arm collides against the disk by the impact force acting on the magnetic disk apparatus.
The countermeasure against the jump of the slider or the suspension proposed in the 2.5 inch magnetic disk apparatus are not effective for restraining the collision of the carriage arm against the disk. As shown in FIG. 2, the out-of-plane rigidity k2z of the spring part of the suspension (rigidity vertical to the plane of the suspension) is designed to be very small as compared with the out-of-plane rigidity k1z of the carriage arm (in order not to deteriorate the follow-up property of the slider to the disk), and no restraint force acts onto the carriage arm from the suspension in an out-of-plane direction.
An object of the present invention is to prevent collision of a carriage arm against a disk by an impact force acting on a magnetic disk apparatus, and to provide new structures to reduce a collision force.
According to one aspect of the present invention, there is provided a magnetic disk apparatus comprises a head slider on which a magnetic head is mounted, a disk on which information is recorded/regenerated by the magnetic head, a spindle motor, integrally structured with the disk, for rotating the disk, a suspension for elastically supporting the magnetic head slider, a carriage arm for supporting the suspension and positioning the magnetic head, and a base plate for attaching the spindle motor and the carriage arm, respectively, wherein an out-of-plane primary natural frequency of the part of the base plate to which the spindle is to be attached is set to be substantially the same as an out-of-plane primary natural frequency of the part of the base plate to which the carriage arm is to be attached; an out-of-plane primary natural frequency of the carriage arm is detached from the out-of-plane primary natural frequency of the base plate part to which the carriage arm is to be attached to such an extent that no resonance occurs; and an out-of-plane primary natural frequency of the disk is detached from the out-of-plane primary natural frequency of the base plate part to which the disk is to be attached to such an extent that no resonance occurs.
According to another aspect of the present invention, there is provided a magnetic disk apparatus comprising: a head slider on which a magnetic head is mounted; a disk on which information is recorded/regenerated by the magnetic head; a suspension for elastically supporting the magnetic head slider; a carriage arm for supporting the suspension and positioning the magnetic head; a suspension mount integrally structured with the suspension, and attached to the carriage arm so that the suspension is held between the carriage arm and the suspension mount; and means, disposed on a tip end of the suspension mount, for relieving the collision of the carriage arm and disk.
In the above-described magnetic disk apparatus, the collision relieving means is a slope disposed on the tip end of the suspension mount so that the contact area with the disk is enlarged during the contact of the suspension mount and disk.
Alternatively, in the above-described magnetic disk apparatus, the collision relieving means is a cushion material disposed on the tip end of the suspension mount.
According to further aspect of the present invention, there is provided a magnetic disk apparatus comprising: a head slider on which a magnetic head is mounted; a disk on which information is recorded/regenerated by the magnetic head; a suspension for elastically supporting the magnetic head slider; a carriage arm for supporting the suspension and positioning the magnetic head; a suspension mount integrally structured with the suspension and attached to the carriage arm so that the suspension is positioned to face the disk; and means, disposed on the part of the suspension opposite to the tip end of the carriage arm, for relieving the collision of the carriage arm and disk.
In the above-described magnetic disk apparatus, the collision relieving means is a rib disposed on the suspension in order to enlarge the contact area with the disk.
Alternatively, in the above-described magnetic disk apparatus, the collision relieving means is a bent part disposed on the suspension in order to enlarge the contact area with the disk.
Alternatively, in the magnetic disk apparatus, the collision relieving means is a cushion material disposed on the suspension.